From 6ba04c2b033942a66ee2af5fde67e091febd9aaa Mon Sep 17 00:00:00 2001
From: Aurelien Jacobs <aurel@gnuage.org>
Date: Sun, 13 May 2007 23:16:56 +0000
Subject: split jpeg_ls into jpeglsdec, jpeglsenc and jpegls

Originally committed as revision 9021 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/jpegls.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)
 create mode 100644 libavcodec/jpegls.c

(limited to 'libavcodec/jpegls.c')

diff --git a/libavcodec/jpegls.c b/libavcodec/jpegls.c
new file mode 100644
index 0000000000..8a6f5065c2
--- /dev/null
+++ b/libavcodec/jpegls.c
@@ -0,0 +1,96 @@
+/*
+ * JPEG-LS common code
+ * Copyright (c) 2003 Michael Niedermayer
+ * Copyright (c) 2006 Konstantin Shishkov
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file jpegls.c
+ * JPEG-LS common code.
+ */
+
+#include "jpegls.h"
+
+const uint8_t ff_log2_run[32]={
+ 0, 0, 0, 0, 1, 1, 1, 1,
+ 2, 2, 2, 2, 3, 3, 3, 3,
+ 4, 4, 5, 5, 6, 6, 7, 7,
+ 8, 9,10,11,12,13,14,15
+};
+
+void ff_jpegls_init_state(JLSState *state){
+    int i;
+
+    state->twonear = state->near * 2 + 1;
+    state->range = ((state->maxval + state->twonear - 1) / state->twonear) + 1;
+
+    // QBPP = ceil(log2(RANGE))
+    for(state->qbpp = 0; (1 << state->qbpp) < state->range; state->qbpp++);
+
+    if(state->bpp < 8)
+        state->limit = 16 + 2 * state->bpp - state->qbpp;
+    else
+        state->limit = (4 * state->bpp) - state->qbpp;
+
+    for(i = 0; i < 367; i++) {
+        state->A[i] = FFMAX((state->range + 32) >> 6, 2);
+        state->N[i] = 1;
+    }
+
+}
+
+/**
+ * Custom value clipping function used in T1, T2, T3 calculation
+ */
+static inline int iso_clip(int v, int vmin, int vmax){
+    if(v > vmax || v < vmin) return vmin;
+    else                     return v;
+}
+
+void ff_jpegls_reset_coding_parameters(JLSState *s, int reset_all){
+    const int basic_t1= 3;
+    const int basic_t2= 7;
+    const int basic_t3= 21;
+    int factor;
+
+    if(s->maxval==0 || reset_all) s->maxval= (1 << s->bpp) - 1;
+
+    if(s->maxval >=128){
+        factor= (FFMIN(s->maxval, 4095) + 128)>>8;
+
+        if(s->T1==0     || reset_all)
+            s->T1= iso_clip(factor*(basic_t1-2) + 2 + 3*s->near, s->near+1, s->maxval);
+        if(s->T2==0     || reset_all)
+            s->T2= iso_clip(factor*(basic_t2-3) + 3 + 5*s->near, s->T1, s->maxval);
+        if(s->T3==0     || reset_all)
+            s->T3= iso_clip(factor*(basic_t3-4) + 4 + 7*s->near, s->T2, s->maxval);
+    }else{
+        factor= 256 / (s->maxval + 1);
+
+        if(s->T1==0     || reset_all)
+            s->T1= iso_clip(FFMAX(2, basic_t1/factor + 3*s->near), s->near+1, s->maxval);
+        if(s->T2==0     || reset_all)
+            s->T2= iso_clip(FFMAX(3, basic_t2/factor + 5*s->near), s->T1, s->maxval);
+        if(s->T3==0     || reset_all)
+            s->T3= iso_clip(FFMAX(4, basic_t3/factor + 6*s->near), s->T2, s->maxval);
+    }
+
+    if(s->reset==0  || reset_all) s->reset= 64;
+//    av_log(NULL, AV_LOG_DEBUG, "[JPEG-LS RESET] T=%i,%i,%i\n", s->T1, s->T2, s->T3);
+}
-- 
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